1. Field of the Invention
The present invention relates to a microwave oven, and more particularly, to a ventilation structure of a microwave oven, which can reduce required number of components, and improve a cooling efficiency, and a lamp fitting structure therefor.
2. Background of the Related Art
The microwave oven is a cooking appliance in which a magnetron is used for generating a microwave, and directing the microwave to a cooking object, to cause molecular movements in the cooking object, for heating the cooking object. The microwave oven of the present invention has a function for absorbing a heat from electric fittings in an electric fitting room, a function for discharging water vapor and the like in a cavity, and a hood function for absorbing and discharging water vapor and the like from a cooker (for an example, a gas oven range) installed below the microwave oven. A related art ventilation structure of a microwave oven, and a lamp fitting structure therefor will be explained with reference to the attached drawings.
Referring to FIGS. 1 and 2, the related art microwave oven is divided into a cavity 1 for heating food, and an electric fitting room 3 for fitting electric components therein. For letting air introduced into the electric fitting room 3 flow into the cavity 1, there is a perforated air inlet at a side of the cavity 1. There is a perforated air outlet 1b in a left part of an upper surface of the cavity 1, for discharging the air in the cavity 1.
Referring to FIG. 2, the electric fitting room 3 has electric components, starting from a magnetron 5, a high voltage transformer 6, fitted therein, and an air guide 7 connected between the air inlet 1a and the magnetron 5 for guiding introduction of the air cooled the magnetron into the cavity 1.
Referring to FIG. 1, there is an air duct 10 on the cavity 1 for guiding air during drawing and discharging of the air. There is a cooling fan 15 in the air duct 10 over the electric fitting room 3. There is a lamping fitting part 10a on one side of the air duct 10. There is a lamp bracket 20 under the lamp fitting part 10a having a fitting hole 20 at a side thereof for fitting the lamp 21. There is a perforated lighting window 1c in an upper surface of the cavity 1 opposite to the lamp 21. The lighting window 1c is formed in one side part of the upper surface of the cavity in the vicinity of the air inlet 1a, for introducing a lamp light into the cavity 1 through the lighting window 1c. There is heat resistant tap 25 fitted to a part over the lighting window 1c, for blocking the air introduced into the cavity 1 through the air inlet 1a to make a smoother air flow toward the air outlet 1b, and protecting a lamp 1 by preventing oil mist or vapor generated during cooking from coming into contact with the lamp 21.
In the meantime, there is a ventilation motor assembly 29 at a central part of the upper surface of the cavity 1 for drawing water vapor and smoke rising from a cooker below the microwave oven, heat generated in the electric fitting room, and the like through fans and inlet openings fitted on both sides thereof, and discharging to an outside of the microwave oven.
Works of the related art ventilation structure of a microwave oven will be explained with reference to the attached drawings.
The air introduced into an upper part of the electric fitting room through a vent grill (not shown) in a front surface of the microwave oven cools down the electric fittings in the electric fitting room 3, such as the magnetron, and the high voltage transformer 6, as the cooling fan rotates 15. The air heated as the magnetron 5 is cooled down is introduced into the cavity 1 through the air inlet 1a formed at a side of the cavity 1 by the air guide 7. Then, the air introduced into the cavity 1 escapes to an outside of the cavity 1 through the air outlet 1b in a left part of the upper surface thereof together with smoke, water vapor, and the like, flows guided by the air duct 10 on the upper part of the cavity 1, and discharged through a vent grill (not shown) in the front surface of the microwave oven.
In the meantime, during cooking in the microwave oven, the light of the lamp 21 passes through the lighting window 1c in one side part of the upper surface of the cavity 1, and lights an inside of the cavity 1. The heat resistant tape 25 attached on the lighting window 1c blocks the air introduced into the cavity 1 through the air inlet 1a from rising to a part over the cavity 1 through the lighting window 1c while transmitting the light. If the heat resistant tape 25 is not attached to the lighting window 1c, the air introduced through the air inlet 1a will not flow to the air outlet 1b, but to the lighting window 1c over the air inlet 1a. In this instance, the air flow for discharging the water vapor in the cavity formed during the cooking out of the cavity 1 is not smooth, to form dew on the door due to a temperature difference between inside and outside of the cavity 1. Moreover, if the heat resistant tape 25 is not attached to the lighting window 1c, electronic components, starting from the lamp 21, are liable to cause short circuit or malfunction, due to moist contained in the air rising through the lighting window 1c. Thus, the attachment of the heat resistant tape 25 to the lighting window 1c is essential in the ventilation system of the related art microwave oven.
However, the related art microwave oven causes the following problem due to a structural limitation of the ventilation system.
The heat resistant tape 25 attached to the lighting window 1c for making a smooth air flow to remove the water vapor from the cavity 1 is expensive as the heat resistant tape 25 is required to have both a good heat resistance and a light transmittivity, to push up a production cost.
In the ventilation structure of the related art microwave oven, since the lamp fitting space is closed in upper part and lower part as an upper surface of the lighting window 1c located below the lamp 21 is blocked by the heat resistant tape 25, and the lamp 21 is fitted to the lamp bracket 20 fitted to a bottom surface of the air duct 10. Therefore, overheat of the lamp 21 caused by failure of rejection of the heat from the lamp shortens a lifetime of the lamp 21.
The comparatively long air duct 10 on the cavity 1 from above the electric fitting room 3 to an upper part of left side of the cavity 1 having the air outlet 1b formed therein requires much material, to push up a production cost, and to make the product heavier.
Accordingly, the present invention is directed to a ventilation structure of a microwave oven that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a ventilation structure of a microwave oven, which can reduce a weight of a product, and a production cost, and prolong a lifetime of the lamp.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the ventilation structure of a microwave oven includes a cavity forming a cooking space therein having an air inlet and lighting window in one side of upper surface thereof for introducing a portion of air introduced into an electric fitting room, and an air outlet in the other side of the upper surface thereof for discharging the air in the cavity to outside of the cavity, a mounting floor at a height the same with the cavity in an upper part of the electric fitting room, for fitting electric components thereon, a ventilation motor assembly fitted to one side of a part over the cavity for drawing water vapor and the like in the cavity through the air outlet and discharging to outside of the cavity, and absorbing a heat generated at the electric fittings in the electric fitting room and discharging the heat, and an air duct fitted to the part over the cavity for separating a passage of air discharged to outside of the cavity through the air outlet and drawn into the ventilation motor assembly, and a passage of air drawn into the ventilation motor assembly through the electric fitting room.
The air duct has a form of box with an opened upper surface, and an outlet in a front surface for discharging air blown by the ventilation motor assembly through a vent grill.
The ventilation structure further includes a guide wall on an upper surface of the cavity for dividing a portion of the air introduced into the electric fitting room and guiding the portion of the air toward the air inlet and lighting window.
The guide wall is formed as one unit with the air duct, or on the upper surface of the cavity as one unit.
The ventilation structure further includes a lamp fitted between the air duct and the air inlet and lighting window for illumination of an inside of the cavity, and the lamp is fitted to a lamp bracket fitted to a bottom of the air duct.
In other aspect of the present invention, there is provided a lamp fitting structure of a microwave oven including a cavity forming a cooking space therein having an air inlet and lighting window in one side of upper surface thereof for introducing a portion of air introduced into an electric fitting room, and an air outlet in the other side of the upper surface thereof for discharging the air in the cavity to outside of the cavity, a mounting floor at a height the same with the cavity in an upper part of the electric fitting room, for fitting electric components thereon, a ventilation motor assembly fitted to one side of a part on the cavity for drawing water vapor and the like in the cavity and discharging to outside of the cavity, and absorbing a heat generated at the electric fittings in the electric fitting room and discharging the heat, an air duct fitted to a part over, and spaced from, the cavity for separating a passage of air discharged to outside of the cavity through the air outlet and drawn into the ventilation motor assembly, and a passage of air drawn into the ventilation motor assembly through the electric fitting room, a lamp bracket fitted between the air duct and the air inlet and lighting window for fitting the lamp, and a lamp fitted to the lamp bracket for illumination of an inside of the cavity.
The lamp bracket is fitted to a bottom of the air duct as one unit.
Therefore, different from the related art, since a back flow of the air through the air inlet and lighting window is prevented, the heat resistant tape attached to the air inlet and lighting window can be dispensed with, to reduce an assembly man-hour, and save a production cost.
Also, since the air introduced into the cavity through the air inlet and lighting window cools down the lamp, a lifetime of the lamp can be prolonged.
The shortened distance between the air inlet and lighting window over the cavity and the air outlet than that of the related art permits to form the air duct smaller, to save a material cost, and reduce weight of the product.
Since the ventilation structure of the present invention permits both the lamp light illumination of the cavity and the introduction of the air into the cavity by using the air inlet and lighting window over the cavity in common, a fabrication process can be simplified and a fabrication cost is saved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.